POS0904 INTENSIVE TRAINING PROGRAM FOR ULTRASOUND-GUIDED MINIMALLY INVASIVE SYNOVIAL TISSUE BIOPSY PROCEDURE ON SMALL AND LARGE JOINTS IN DIFFERENT PHASES OF JOINT INFLAMMATION
Authors: L. A. Coletto, V. Marino, C. Rizzo, L. Verardi, D. Bruno, P. Rubortone, N. Goulas, A. D’antonio, M. Gessi, C. DI Mario, B. Tolusso, L. Bui, M. S. Chimenti, G. Guggino, F. Ciccia, R. Caporali, E. Gremese, M. A. D’agostino, M. M. Lizzio, S. Alivernini
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Ultrasound (US)-guided minimally invasive technique has improved the availability of soft tissue specimens, as synovial tissue (ST), to be used for basic and translational studies. However, to date, there is a lack of standardized programs to systematically train rheumatologists in its performance on joints in different disease stages of inflammation. <h3>Objectives</h3> (i) to develop an intensive training program for US-guided ST biopsy on large and small joints across inflammatory arthritis phases; (ii) to assess the learning curve, sample quality and trainees' expectations and perceptions. <h3>Methods</h3> Rheumatoid arthritis (RA) patients with active disease or in sustained remission were included in the study. Eight trainees in rheumatology with basic skills on musculoskeletal US joined the training program consisting of 4 sequential phases: (i) observation of the procedure performed by the trainer, (ii) performance of guided step-by-step phases of the procedure, (iii) execution of the whole procedure on small and large joints in parallel with the trainer as reference (each one carried out on paired joints with comparable US-defined joint inflammation on the same patient) and (iv) performance of the complete procedure autonomously. ST specimens were processed for histology (H&amp;E) to assess sample quality in terms of anatomical representativity given by lining and sublining layers presence, required for the semiquantitative assessment of synovitis degree using Krenn score. Before and after the program, trainees' expectations and perceptions were collected using a questionnaire. <h3>Results</h3> 236 ST biopsy procedures were included in the analysis. After completing the observational and guided step-by-step phases, trainees conducted complete procedures (n=44) in parallel with the trainer performing the procedure on the contralateral joint [n=36 knees (n=24 inflamed and n=12 in remission) and n=8 inflamed wrists] showing comparable rate of informative samples recovered by trainees on knees in terms of lining (91.4% and 83.3% for active and remission knees, respectively) and sublining (100% for both) presence, compared to the trainer's procedures (p&gt;0.05). Conversely, the rate of informative samples retrieved from active wrists by trainees was lower in terms of lining layer (62.5%), but not sublining layer (100%) presence, compared to the trainers (100% for both, p=0.05). Then, trainees performed n=148 procedures without the trainer guidance (n=74 on active and n=43 remission knees respectively, and n=31 on active wrists) achieving an excellent rate of informative samples of 93.3% and 90.3% on active knees and wrists respectively but lower (72.1%, p=0.0017) on remission knees, always due to the lack of lining layer retrieval. After the training completion, the trainees' expectation about the invasiveness and pain infliction related to the procedure decreased (p=0.0625 and p=0.0156, respectively). However, after the training program, trainees' perception of the difficulty of executing the procedure decreased only for large joints regardless to the inflammatory status (p=0.0312) remaining unchanged for small joints (p=0.0625). <h3>Conclusion</h3> This intensive multi-step program is an effective training system for developing advanced skills in the performance of US-guided ST biopsy on large and small joints, providing high quality specimens to be used for basic and translational studies on chronic inflammatory joint diseases as RA. The intensity and the timing of the training needed to reach acceptable success rates, might be adjusted according to the inflammatory status and the location of the procedure. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.